Rotary pump



Dec. 16, 1952 MAR-"N 2,621,604

ROTARY PUMP Filed May 4, 1948 A I II II INVENTOR. G06 f MART/N Patented Dec. 16, 1952 2,621,604 ROTARY PUMP George F. Martin, Oakland, Calif., assignor of one-half to Peter A. Battagla Application May 4, 1948, Serial No. 24,991

1 Claim. 1

This invention relates to pumps and particu' larly to rotary pumps of the sliding vane type.

An object of the invention is to provide a pump of the radial sliding vane type wherein movement of one of a pair of vanes afiects advantageously the movement of the other vane of the pair and thereby increases the efficiency of the pump.

Another object of the invention is to provide a pump of the radial vane type which has high ciliciency irrespective of wide speed variations.

A further object of the invention is to provide in a pump of the character described a plurality of movable vanes which engage the pump cylinder with optimum and equal effective pressure throughout every revolution.

A still further object is to provide a pump of high efiiciency and long life which is capable of being produced at a relatively low cost.

The invention possesses other objects and features of advantage, some of which, with the foregoing, will be set forth in the following description of the preferred form of the invention which is illustrated in the drawings accompanying and forming part of the specification. It is to be understood, however, that variations in the showing made by the said drawings and description may be adopted within the scope of the invention as set forth in the claim.

Referring to the drawings:

Figure 1 is a longitudinal vertical sectional view of the pump of my invention, the view being taken in the plane indicated by the line l-l of Figure 2. v

Figure 2 is a vertical sectional view of the pump taken in the plane indicated by the line 2-2 of Figure 1.

Figure 3 is a vertical sectional view of the pump taken on the line 3-3 of Figure 1, the rotor assembly having been omitted for the sake of clarity. I

Figure 4 is an enlarged sectional view showing the ball and socket connection of the spring linkage.

In the type of structure in which I have chosen to illustrate my invention, I provide a cylindrical casing 6, the open ends of which are closed by a pair of end plates 1 to define a pump chamber 9. The end plates 1 are provided with intake and exhaust ports in and II respectively, manifolds 8,

and an eccentrically positioned base 12 having an axial bore 13 extending therethrough which opens into and is concentric with a recess l4 formed on the inner side of the end plate facing the pump chamber. Also each end plate I is provided with a number of marginal ears I5 which are bored to receive rods l6 and associated end nuts for maintaining the unitary assembly of end plates 1 and cylindrical casing 6. Similar rods I! extend through apertures l8 and 19 in the upper and lower portions of the end plates to equalize the circumferential stresses. Bearings 20 of suitable type, preferably the enclosed ball bearings shown,

are provided in each recess l4 and have'their central bores axially registered with the bores [3 of the end plates. In addition, each end plate is provided with a large circular recess 2| facing the pump chamber and concentric with the bearing 20. A still larger circular recess 22, eccentric with respect to the bearing 20 but concentric with respect to the radial disposition of the apertures 18 and I9, and those of the marginal ears l5, forms a peripheral abutment for reception of the cylinder 6 as shown in Figures 1 and 2. Thus it will be seen that the unitary assembly of end plates 1 and cylinder 6 provides bores l3 and 2| which are in axial registry with the axis of cylinder 6 for a purpose now to be described.

A pump rotor is provided in the chamber 9 comprising in part, a pair of circular end plates 23 disposed and fitting with a minimum of radial clearance in the respective recesses 2|, one of the end plates having preferably an integral solid shaft 24 extending therefrom through one of the bearings 20 and its aligned aperture [3, and the other end plate having an integral centrally bored shaft extension 25 thereon extending into the bore of the other bearing 20. The shaft 24, which continues exteriorly of the pump, is provided with a keyway 26, or other suitable means, for securing to the shaft a pulley or the like forming part of a power transmission system by means of which the shaft 24 may be rotated. Oil seals 21, of any suitable and desirable type, are provided in the bases I2 to prevent oil from within the chamber 9 from traveling exteriorly along the shaft 24 and the end plug 29 which is provided with the bored lubricating fitting 28 threaded thereto and which is press fitted or otherwise secured in the end plate bore enclosing the shaft 25. further specific description of such lubricating systems, reference may be had to my concurrently filed, copending patent application Serial No. 20,545, filed April 12, 1948.

Disposed between and uniting the circular end plates 23 is a tubular rotor comprising a pair of body members 30 of semicylindrical cross-sectional form as shown in Figures 1 and 2. Each body member 30 is preferably provided at its respective ends with an inwardly extending peripheral flange 3| having relatively spaced reamed and threaded apertures 32 and 33 therein corresponding with similar apertures provided in the end plates 23, the reamed apertures 32 receiving dowel pins therein and the threaded apertures receiving screws 34 by means of which the pair of body members 30 and the end plates 23 may be secured together as an integral cylindricallyshaped unit. The purposes of the dowel pins are primarily to accurately axially align the as-' sembled rotor elements and secondarily to remove from the screws 34 the strain of transmittin-g rotative force from the driven end plate 23 to the rotor body members 30. It will be noted by reference to Figure 2 that the longitudinal edges 35 of the body members 30, including the ends of the flanges 3|, are provided with correspondingly opposite curvatures of a'radius preferably greater than the radius of the circular end plates 23 and inscribed from diametrically opposite points located inside the body members 30. The edges 35 of the body members 30 are spaced For to provide therebetween, when assembled with the end plates, a pair of diametrically opposed slots extending longitudinally of the rotor and paralleling the axis thereof. These slots are provided to receive slidable, complementarily curved vanes 36 having their outer longitudinal edges in sliding engagement with the inner surface of the casing 6 and each of such vanes is attached to the inner base 31 of an integral frame member having side arms 38 and an outer bridge portion 39 terminating in bored lugs 46 through which a rod 4! extends and is fixed in position by screws 42. The ends of the rod 4| are journaled in suitable bearings 43 provided in locally enlarged portions of the peripheral flange 31 of the rotor. Centrally of the inner base 31 is threadedly. secured a stud having a bell-shaped head 43 which is nested in a socket member 44 provided with a groove in its periphery for the retention of a coil spring 45 which has its opposite end retained in v a similar groove of a socket member secured to the opposite inner base member 37 as clearly shown in Figure 2. Any suitable means may be provided for retaining the heads 43 in the recesses of the socket members 44 as, for example, by displacing portions of the socket member metal bordering the recesses by means of centerpunched indentations so as to embrace the heads 43 but to allow free movement of the heads in the recesses. The spring 45 is of such length as to serve as a resilient linkage between the opposite vanes 36 and forces the outer ends of the vanes against the inner wall of the casing 6 to effect a fluid-tight seal therewith. Since the spring acts on the end of each frame member sup- I porting the vanes, each vane receives the same spring pressure and due to the ball and socket mounting of the spring the force of the latter is always applied in a straight line direction regardless of the relative positions of the vanes.

Since as was stated above, the axis of the shaft 24 is disposed eccentrically with respect to the axis of the pump chamber 6, it will be seen that, as shown in Figure 2, the rotor will be positioned with its periphery in close tangential relation to the inner peripheral surface of the casing 6 thus forming a crescent-shaped passage radially traversed by and through which the vanes 36 may successively move as the rotor rotates. The arrangement is such that the points of greatest constriction of the passage are situated intermediate the respective port openings and II while the point of greatest cross-sectional area of the passage is oppositely situated midway between the openings. Thus as the rotor is revolved in a preferably counter-clockwise direction as viewed in Figure 2, the vane which crosses and recedes from the opening I!) will create suction to draw fluid to be pumped through the latter opening into the pump chamber 6; whereupon the followin vane will push the fluid ahead of it, through the passage and will forcibly eject the fluid from the chamber through the opening II and the upper manifold 8. Due to the pivotal mounting of the vanes 36 about the bearings 43, the former will be positively guided during their inward and outward movements, through the rotor slots without any frictional engagement with the slot surfaces 35. This entirely climates wear on the curved surfaces of the vanes and slots and also measurably reduces the resistance to movement of the vanes which such frictional engagement would cause. The pump of my invention is therefore more free in its action especially under maximum load and pressures than are the conventional pumps of this type and its resistance to ordinary wear renders it capable of a longer useful life.

The manifold advantages of providing a spring linkage between the opposed pump vanes according to my invention will be easily apparent upon a consideration of pump operation over a Wide range of operating speeds. Thus at low speeds of rotation the vane approaching the exit opening will be sealingly pressed against the curved wall of the pump chamber by the spring linkage, and as this vane moves outward, the spring will also move outward due to the corresponding inward movement of the opposite vane. Thus a comparatively small degree of spring extension and compression takes place and a high pumping efficiency for relatively low rotation speeds results due to the maintenance of equalized spring pressure. The spring linkage in no way impairs the expected efiiciency at high rotating speeds since the added effect of centrifugal force is such as to force the vanes against the wall of the pump chamber in sealing engagement, and the spring elongates accordingly. The provision of the ball and socket connection for the spring ends is particularly desirable since it insures a straight line application of spring action between the vanes throughout the entire rotation of the rotor and through all rotative speeds.

The further advantages of ease of dismantling and replacement of Worn parts will be readily apparent from the constructional details of my improved pump as shown on the drawings.

I claim:

A pump comprising a casing having a pump chamber therein provided with relatively spaced inlet and outlet openings, a substantially hollow cylindrical rotor journaled in said pump chamber and positioned radially eccentrically thereof, arcuately shaped vanes extending outwardly of the periphery of said rotor and engaging the peripheral surface of said pump chamber for moving fluid, as the rotor is revolved, through the pump chamber between the inlet and outlet openings thereof, each of said vanes having an arm secured thereto, said arm being pivotally secured to said rotor at the end thereof remote from its connection with the vane and at a point substantially coinciding with the center of curvature of the vane, said vanes being positioned on said arms so as to present a concave surface to the fluid in the direction of rotation of said rotor, and said vanes being movable relative to the rotor, as the latter is revolved, about said pivot points, spring means within said rotor and ball and socket connectors between said arms and said spring means for transmitting a straightline outward force from said spring means upon said vanes during pump operation.

GEORGE F. MARTIN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 364,925 Hills et al June 1 1, 1887 501,864 Boening et al July 18, 1893 511,311 Temple Dec. 19, 1893 1,507,611 Leigh Sept. 9, 1924 1,645,069 Peterson Oct. 11, 1927 1,683,143 Peterson Sept. 4, 1928 1,858,681 Olson May 11, 1932 

